This invention relates to a method and apparatus for packaging fluent material such as liquids and, in particular, to the rapid filling and sealing of inexpensive, disposable individual containers with metered amounts of such liquids.
The use of individualized servings of such commonly used liquids as cream, milk, salad dressing and the like in restaurants and by airlines in disposable packages has become highly desirable because of the great convenience and cleanliness offered by such packaging. It is necessary, however, that the packaging of the individual servings of fluent material, such as cream or milk, in plastic or paper containers be accomplished under sanitary conditions and in a fast, inexpensive, continuous process with a minimum of handling and spillage. Various methods and apparatus have been designed for accomplishing such results. Two such packaging apparatus and methods are shown in U.S. Pat. No. 3,775,934 to Louis W. Smith, issued Dec. 4, 1973, and U.S. Pat. No. 3,440,794 to Martin Mueller, issued Apr. 29, 1969. The packaging apparatus represented by the above patents, and other apparatus presently used, generally include a conveyor belt for carrying empty containers for the liquid to be packaged, a dispenser for depositing such empty containers on the belt at a first station, a mechanism for filling each container with a desired amount of liquid, and a capping device for applying a fluid-tight cover to the filled container prior to its discharge from the belt.
While most present packaging apparatus perform the basic filling and capping functions, they have certain limitations which have restricted their performance. For example, many present packaging machines require the conveyor belt to be intermittently started and stopped, as, for example, at the filling station. This consumes time and reduces output. Those packaging machines which use a continuously moving belt, such as Mueller, are limited because they are only able to fill a single row or line of containers simultaneously. This limitation also restricts the maximum output of the machine. For example, the machine shown in U.S. Pat. No. 3,775,934 has a maximum output of approximately 300 cups per minute.
Another problem in present machines has been to provide reliable, fluid-tight sealing of the cover to the filled container. This is presently accomplished, as shown in Smith, by a rather long series of heater plates and rollers, which do not always achieve satisfactory results because they only heat the covering material for a brief time after its application to the filled containers.